This invention relates to a fan head swinging device, particularly to one capable to swing right and left for any angle.
A conventional fan head swinging device shown in FIGS. 1 and 2, includes a speed reducer A consisting of plural gears A0 rotated by a synchronous motor B, the motor B has no carbon brushes, and a coil B3 powered to excite magnetism to produce a magnetic field to let the rotor B0 of the motor B to rotate. Then a spindle B1 is connected to the rotor B0, and a gear B2 is fixed on the spindle B1 and engages one of the plural gears A0 of the speed reducer A, causing the head to swing right and left. As the synchronous motor used in the conventional fan has no carbon brushes, which means the excited magnetic field produced between the rotating direction of the rotor B0 and the coil B3 has no constant direction. Therefore, the swinging direction of the fan head cannot be controlled as it should be, and the fan head may be liable to swing reverse if it might receive an exterior force. So an outer wind guider C provided in a cool fan shown in FIG. 3 may change its rotating direction if it is touched. Some traditional fan are provided with a control rod D as shown in FIG. 4 for controlling the fan head in changing its swinging direction, owing to the disadvantage of the synchronous motor in impossibility to control a fan head in swinging correctly.
The objective of the invention is to offer a fan head swinging device to swing right and left for any angle correctly.
The feature of the invention is a speed reducer connected to a DC motor capable to control in changing the rotating direction of the motor, and subsequently possible to control accurately the swinging angle of a fan head.